Sutra Sthana Chapter 6. Seasonal Regimen or Qualitative Dietetics
Keywords: Adana kala, lifestyle, ritu, ritucharya, satmya, seasonal regimen, strength in seasons,visarga kala
|Section/Chapter||Sutra Sthana Chapter 6|
|Preceding Chapter||Matrashiteeya Adhyaya|
|Succeeding Chapter||Naveganadharaniya Adhyaya|
|Other Sections||Nidana Sthana, Vimana Sthana, Sharira Sthana, Indriya Sthana, Chikitsa Sthana, Kalpa Sthana, Siddhi Sthana|
- 1 Introduction
- 2 Sanskrit text, Transliteration and English Translation
- 2.1 Benefits of following seasonal regimen
- 2.2 Six seasons according to (the position of the) Sun
- 2.3 Adana kala (the period with less strength) and visarga kala (the period with good strength)
- 2.4 Diet and lifestyle guidelines in Hemant ritu (Winter season)
- 2.5 Diet and lifestyle guidelines in vasanta ritu (spring season)
- 2.6 Diet and lifestyle guidelines in grishma ritu (summer season)
- 2.7 Diet and lifestyle guidelines in varsha ritu (rainy season)
- 2.8 Diet and lifestyle guidelines in sharada ritu (autumn season)
- 2.9 Okasatmya(acquired adaptation or habituation)
- 2.10 Summary
- 3 Tattva Vimarsha
- 4 Vidhi vimarsha
- 4.1 Division of samvatsara (year) and ritus
- 4.2 Formation of Seasons
- 4.3 Qualities of seasons
- 4.4 Importance of ritucharya
- 4.5 Basic principles of ritucharya
- 4.6 Dosha - rasa relationship
- 4.7 Concept of ritu sandhi
- 4.8 Concept of satmya and okasatmya
- 4.9 Charya / Characteristics of different Seasons
- 4.9.1 Hemanta ritucharya (Regimen for Early winter)
- 4.9.2 Shishira ritucharya (Regimen for Late winter)
- 4.9.3 Vasanta ritucharya (Regimen for Spring)
- 4.9.4 Grishma ritucharya (Regimen for Summer)
- 4.9.5 Varsha ritucharya (Regimen for Rainy season)
- 4.9.6 Sharada ritucharya (Regimen for Autumn)
- 4.9.7 Effect of seasonal changes on health
- 5 References
- 6 Glossary
The primary objective of Ayurveda is to maintain good health. Ahara (food) is the main basis of life, which should be taken in proper quantity and quality to maintain equilibrium and to promote strength, luster and healthy long life. It has been observed that a person taking food even in proper quantity may suffer from diseases in different seasons. It implies that apart from the quantity of ahara (diet), the knowledge of regimen for different seasons also plays a significant role in the maintenance of health and prevention of diseases.
A person who has the knowledge of appropriate food articles and activities applicable to specific seasons and also the discipline and inclination to practice them (in accordance with those seasons) stays healthy, whereas a person without the knowledge (or with limited knowledge) of wholesome regimen for different seasons or without the discipline or temperament of following these seasonal practices is likely to suffer from various diseases. Seeking this objective, the chapter describes the ahara (diet) and vihara (behavior) to be followed in different seasons. The way we eat, exercise, rest, sleep, think, plan, carry out our routine work, and behave with others - are collectively termed Lifestyle. A year is divided into six seasons either on the basis of the position of the Sun with respect to the Earth or on the basis of purification period of dosha or on the basis of rashi (stellar constellations) or other geographical considerations such as traveling, etc. The qualities of different seasons need to be understood in three aspects viz. masa (month), rashi (stellar constellations) and svarupa (characteristic features pertaining to the season). While prescribing regimen for different seasons, importance should be given first to the appearance of svarupa in the prevailing season, then to the rashi and finally to the masa.
Health is a state of dynamic equilibrium between a man and his environment. The moment this Loka-Purusha Samya gets disturbed, doshas get imbalanced to cause diseases. The basic concept of prevention and cure of diseases is based on the tridosha (collective term for vata, pitta, and kapha dosha) theory. A particular rhythmic pattern of the three dosha i.e. sanchaya (accumulation), prakopa (excitation) and prashamana (alleviation) occur in relation to six seasons, when the sun changes from one rashi to the other. Six different rasas present in our food have direct effect on three doshas. Ritusatmya or seasonal adaptation is described under ritucharya (seasonal regimen), which is the variation in ahara and vihara to balance rhythmic seasonal variations of dosha, bala, agni, and rasa etc. through the concept of samanya and vishesha. Knowledge and regular observance of suitable ritucharya (ahara and vihara for different seasons) is mainly for the maintenance of health and prevention of diseases. For diseased persons ritucharya need to be modified accordingly.
Adana kala or uttarayana (northward movement of the Sun) includes shishira (late winter), vasanta (spring) and grishma (summer) ritus and during visarga kala or dakshinayana (southward movement of the Sun) includes varsha (rainy), sharad (autumn) and hemanta (early winter) ritus or seasons. In these ritus there are specific changes in atmospheric conditions which influence changes in dosha, bala (body strength) and agni (digestive power). These atmospheric changes affect all living beings in the universe. Due to changes in the external environment, the tridosha automatically pass through three different phases i.e. sanchaya (accumulation), prakopa (excitation) and prasamana (alleviation).
To maintain the balance of rhythmic seasonal variations of dosha, bala, agni, and rasa in our body (samya/normalcy/health), Ayurveda has prescribed specific ahara and vihara to be followed (prashasta) and to be avoided (varjya) during six different seasons in terms of ritucharya (seasonal regimen). Special emphasis has been given to ritusandhi, the transitional phase of 14 days between two seasons. During this period the ritucharya of both seasons need to be observed in a specific manner (padanashikha krama). At the end of this chapter, satmya and okasatmya have been explained. Any naturally suitable food or behavior beneficial to the self is considered as satmya. Okasatmya is anything unnatural, unacceptable and acquired habituation to food and lifestyle. Even though, it has become a habit, it should be stopped gradually.
In this fast moving era of science and technology, lifestyle changes in the form of non-observance of ritucharya is a major risk factor for increasing prevalence of various diseases. The concept of ritucharya, in terms of self-management of lifestyle should be promoted universally for health and prevention of diseases in all individuals.
Sanskrit text, Transliteration and English Translation
अथातस्तस्याशितीयमध्यायं व्याख्यास्यामः||१|| इति ह स्माह भगवानात्रेयः||२||
Athātastasyāśitīyamadhyāyaṁ vyākhyāsyāmaḥ||1|| Iti ha smāha bhagavānātrēyaḥ||2||
athAtastasyAshitIyamadhyAyaM vyAkhyAsyAmaH||1|| iti ha smAha bhagavAnAtreyaH||2||
Now I shall expound upon Tasyashiteeya Adhyaya (the chapter on diet and behavior during different seasons). Thus, said Lord Atreya [1-2]
Benefits of following seasonal regimen
तस्याशिताद्यादाहाराद्बलं वर्णश्च वर्धते| यस्यर्तुसात्म्यं विदितं चेष्टाहारव्यपाश्रयम्||३||
Tasyāśitādyādāhārādbalaṁ varṇaśca vardhatē| yasyartusātmyaṁ viditaṁ cēṣṭāhāravyapāśrayam||3||
tasyAshitAdyAdAhArAdbalaM varNashca vardhate| yasyartusAtmyaM viditaM ceShTAhAravyapAshrayam||3||
A person who knows the ritusatmya, i.e., getting accustomed to suitable changes in diet and behavior according to seasons, and practices such habits accordingly, and whose diet consists of various types of food articles (with properties such as ashita, pitta lidha , and khadita), has his strength and luster enhanced, and he leads a healthy, long life.
Six seasons according to (the position of the) Sun
इह खलु संवत्सरं षडङ्गमृतुविभागेन विद्यात्| तत्रादित्यस्योदगयनमादानं च त्रीनृतूञ्छिशिरादीन् ग्रीष्मान्तान् व्यवस्येत्, वर्षादीन् पुनर्हेमन्तान्तान् दक्षिणायनं विसर्गं च||४||
Iha khalu saṁvatsaraṁ ṣaḍaṅgamr̥tuvibhāgēna vidyāt| tatrādityasyōdagayanamādānaṁ ca trīnr̥tūñchiśirādīn grīṣmāntān vyavasyēt, varṣādīn punarhēmantāntāndakṣiṇāyanaṁ visargaṁ ca||4||
iha khalu saMvatsaraM ShaDa~ggamRutuvibhAgena vidyAt| tatrAdityasyodagayanamAdAnaM ca trInRutU~jchishirAdIn grIShmAntAn vyavasyet, varShAdIn punarhemantAntAn dakShiNAyanaM visargaM ca||4||
A year (samvatsara) is divided into six parts (by seasons). Amongst them, when the Sun is in uttarayana (northward to the Earth), that part of the year is called adana kala and includes three ritus starting from shishira to grishma (shishira, vasanta and grishma). When the Sun is in dakshinayana (southwards of the Earth), the period is called visarga kala and includes three ritus starting from varsha to hemanta (varsha, sharad and hemanta). This segmentation of the year (by seasons) is for the purpose of swasthavritta (healthy regimen) in different seasons.
Adana kala (the period with less strength) and visarga kala (the period with good strength)
विसर्गे पुनर्वायवो नातिरूक्षाः प्रवान्ति, इतरे पुनरादाने; सोमश्चाव्याहतबलः शिशिराभिर्भाभिरापूरयञ्जगदाप्याययति शश्वत्, अतो विसर्गः सौम्यः| आदानं पुनराग्नेयं; तावेतावर्कवायू सोमश्च कालस्वभावमार्गपरिगृहीताः कालर्तुरसदोषदेहबलनिर्वृत्तिप्रत्ययभूताःसमुपदिश्यन्ते||५||
Visargē punarvāyavō nātirūkṣāḥ pravānti, itarē punarādānē; sōmaścāvyāhatabalaḥśiśirābhirbhābhirāpūrayañjagadāpyāyayati śaśvat, atō visargaḥ saumyaḥ| Adānaṁ punarāgnēyaṁ; tāvētāvarkavāyū sōmaśca kālasvabhāvamārgaparigr̥hītāḥkālarturasadōṣadēhabalanirvr̥ttipratyayabhūtāḥ samupadiśyantē||5||
visarge punarvAyavo nAtirUkShAH pravAnti, itare punarAdAne; somashcAvyAhatabalaH shishirAbhirbhAbhirApUraya~jjagadApyAyayati shashvat, ato visargaHsaumyaH| AdAnaM punarAgneyaM; tAvetAvarkavAyU somashca kAlasvabhAvamArgaparigRuhItAH kAlarturasadoShadehabalanirvRuttipratyayabhUtAH samupadishyante||5||
In visarga kala (period of emission) the wind is not as dry as it is in adana kala. In this visarga kala the power of moon is dominant (as it is nearer to the earth), and it continuously replenishes/delights the world with its cooling rays. Hence, visarga kala is saumya (soothing) in nature.
Contrary to this, adana kala is agneya (heating) in nature. The Sun, wind and the Moon all are governed by time, and the path they follow in a year is responsible for different variations of kala (time), ritu (seasons), rasa (tastes), dosha (humors) and deha bala (body strength).
तत्र रविर्भाभिराददानो जगतः स्नेहं वायवस्तीव्ररूक्षाश्चोपशोषयन्तः शिशिरवसन्तग्रीष्मेषु यथाक्रमं रौक्ष्यमुत्पादयन्तो रूक्षान् रसांस्तिक्तकषायकटुकांश्चाभिवर्धयन्तो नृणां दौर्बल्यमावहन्ति||६||
Tatra ravirbhābhirādadānō jagataḥ snēhaṁ vāyavastīvrarūkṣāścōpaśōṣayantaḥ śiśiravasantagrīṣmēṣuyathākramaṁ raukṣyamutpādayantō rūkṣān rasāṁstiktakaṣāyakaṭukāṁścābhivardhayantō nr̥ṇāṁdaurbalyamāvahanti||6||
tatra ravirbhAbhirAdadAno jagataH snehaM vAyavastIvrarUkShAshcopashoShayantaH shishiravasantagrIShmeShu yathAkramaM raukShyamutpAdayanto rUkShAnrasAMstiktakaShAyakaTukAMshcAbhivardhayanto nRuNAM daurbalyamAvahanti||6||
In adana kala the Sun with its hot rays absorbs moisture from the Earth/environment and the sharp and dry wind by its absorbing nature further causes dryness in shishira, vasanta, and grishma ritus progressively, leading to the predominance of tikta, kashaya, and katu rasa respectively and gradual increase of weakness in human beings during these three ritus. 
वर्षाशरद्धेमन्तेषु तु दक्षिणाभिमुखेऽर्के कालमार्गमेघवातवर्षाभिहतप्रतापे, शशिनि चाव्याहतबले, माहेन्द्रसलिलप्रशान्तसन्तापे जगति, अरूक्षा रसाः प्रवर्धन्तेऽम्ललवणमधुरा यथाक्रमं तत्र बलमुपचीयते नृणामिति||७||
Varṣāśaraddhēmantēṣu tu dakṣiṇābhimukhē'rkē kālamārgamēghavātavarṣābhihatapratāpē, śaśinicāvyāhatabalē, māhēndrasalilapraśāntasantāpē jagati, arūkṣā rasāḥ pravardhantē'mlalavaṇamadhurāyathākramaṁ tatra balamupacīyatē nr̥ṇāmiti||7||
varShAsharaddhemanteShu tu dakShiNAbhimukhe~arke kAlamArgameghavAtavarShAbhihatapratApe, shashini cAvyAhatabale, mAhendrasalilaprashAntasantApejagati, arUkShA rasAH pravardhante~amlalavaNamadhurA yathAkramaM tatra balamupacIyate nRuNAmiti||7||
In varsha, sharad and hemanta ritu, the Sun is situated in southwards position and its heating power slackens due to the effect of time, its position with respect to the Earth, clouds, wind, and rain. The power of the Moon is predominant. Rainwater diminishes the heating effect of nature. All of these lead to the predominance of non-dry, amla (sour), lavana (salty), and madhura (sweet) rasa respectively and there is gradual increase of body strength in human beings during these three months. 
भवन्ति चात्र- आदावन्ते च दौर्बल्यं विसर्गादानयोर्नृणाम्| मध्ये मध्यबलं, त्वन्ते श्रेष्ठमग्रे च निर्दिशेत्||८||
Bhavanti cātra- ādāvantē ca daurbalyaṁ visargādānayōrnr̥ṇām| madhyē madhyabalaṁ, tvantē śrēṣṭhamagrē ca nirdiśēt||8||
bhavanti cAtra- AdAvante ca daurbalyaM visargAdAnayornRuNAm| madhye madhyabalaM, tvante shreShThamagre ca nirdishet||8||
In the beginning of visarga kala and at the end of adana kala, human beings on the Earth experience weakness. In the middle of these two kala or periods, humans possess medium strength. At the end of the visarga kala and at the beginning of adana kala the strength in human beings is maximum. 
Diet and lifestyle guidelines in Hemant ritu (Winter season)
शीते शीतानिलस्पर्शसंरुद्धो बलिनां बली| पक्ता भवति हेमन्ते मात्राद्रव्यगुरुक्षमः||९||
śītē śītānilasparśasaṁruddhō balināṁ balī| paktā bhavati hēmantē mātrādravyagurukṣamaḥ||9||
shIte shItAnilasparshasaMruddho balinAM balI| paktA bhavati hemante mAtrAdravyagurukShamaH||9||
During sheeta kala (hemanta) due to the contact of cold wind, the agni (digestive fire) of strong/healthy individuals gets trapped in the body (like in a closed chamber) and becomes strong or powerful. So, the agni becomes powerful enough to digest food that is heavy not just in quantity as well as in nature. 
स यदा नेन्धनं युक्तं लभते देहजं तदा| रसं हिनस्त्यतो वायुः शीतः शीते प्रकुप्यति||१०||
sa yadā nēndhanaṁ yuktaṁ labhatē dēhajaṁ tadā| rasaṁ hinastyatō vāyuḥ śītaḥ śītē prakupyati||10||
sa yadA nendhanaM yuktaM labhate dehajaM tadA| rasaM hinastyato vAyuH shItaH shIte prakupyati||10||
If adequate food is not made available to the body, then this strong agni consumes/absorbs the rasa-the intrinsic fluids of the body. Vata having sheeta (cold) quality gets vitiated in this sheeta kala (cold season).
तस्मात्तुषारसमये स्निग्धाम्ललवणान् रसान्| औदकानूपमांसानां मेद्यानामुपयोजयेत्||११||
बिलेशयानां मांसानि प्रसहानां भृतानि च| भक्षयेन्मदिरां शीधुं मधु चानुपिबेन्नरः||१२||
Tasmāttuṣārasamayē snigdhāmlalavaṇān rasān| audakānūpamāṁsānāṁ mēdyānāmupayōjayēt||11||
bilēśayānāṁ māṁsāni prasahānāṁ bhr̥tāni ca| bhakṣayēnmadirāṁ śīdhuṁ madhu cānupibēnnaraḥ||12||
rasAn| audakAnUpamAMsAnAM medyAnAmupayojayet||11||
bileshayAnAM mAMsAni prasahAnAM bhRutAni ca| bhakShayenmadirAM shIdhuM madhu cAnupibennaraH||12||
In the period of snowfall (tushara kala), unctuous, sour and salty food items should be taken predominantly. Meat of fatty, aquatic and marshy animals should be taken. Meat of burrowing animals and roasted meat of animals that eat by snatching should be consumed and after that drinking of madira and sidhu type of wines and honey is advised. [11-12]
गोरसानिक्षुविकृतीर्वसां तैलं नवौदनम्| हेमन्तेऽभ्यस्यतस्तोयमुष्णं चायुर्न हीयते||१३||
gōrasānikṣuvikr̥tīrvasāṁ tailaṁ navaudanam| hēmantē'bhyasyatastōyamuṣṇaṁ cāyurna hīyatē||13||
gorasAnikShuvikRutIrvasAM tailaM navaudanam| hemante~abhyasyatastoyamuShNaM cAyurna hIyate||13||
A person who is habituated to consuming milk products, cane sugar products, fats and oils, new rice and warm water during hemanta ritu, never sees his lifespan decrease ( i.e. these help in prevention from early aging and diseases). 
अभ्यङ्गोत्सादनं मूर्ध्नि तैलं जेन्ताकमातपम्| भजेद्भूमिगृहं चोष्णमुष्णं गर्भगृहं तथा||१४||
abhyaṅgōtsādanaṁ mūrdhni tailaṁ jēntākamātapam| bhajēdbhūmigr̥haṁ cōṣṇamuṣṇaṁ garbhagr̥haṁ tathā||14||
abhya~ggotsAdanaM mUrdhni tailaM jentAkamAtapam| bhajedbhUmigRuhaM coShNamuShNaM garbhagRuhaM tathA||14||
In hemanta ritu, massage (unction/anointing), oil on the head, fomentation by jentaka (a type of fomentation/sudation) method, sunbath, spending time in hot underground houses and warmer, inner rooms of the house is indicated. 
शीतेषु संवृतं सेव्यं यानं शयनमासनम्| प्रावाराजिनकौषेयप्रवेणीकुथकास्तृतम्||१५||
śītēṣu saṁvr̥taṁ sēvyaṁ yānaṁ śayanamāsanam| prāvārājinakauṣēyapravēṇīkuthakāstr̥tam||15||
shIteShu saMvRutaM  sevyaM yAnaM shayanamAsanam| prAvArAjinakauSheyapraveNIkuthakAstRutam||15||
In winters vehicles, beds and seats should be well covered and spread over with thick quilts, deer or tiger skins, silken sheets, gunny-cloth sheets or blankets. 
गुरूष्णवासा दिग्धाङ्गो गुरुणाऽगुरुणा सदा| शयने प्रमदां पीनां विशालोपचितस्तनीम्||१६||
आलिङ्ग्यागुरुदिग्धाङ्गीं सुप्यात् समदमन्मथः| प्रकामं च निषेवेत मैथुनं शिशिरागमे||१७||
gurūṣṇavāsā digdhāṅgō guruṇā'guruṇā sadā| śayanē pramadāṁ pīnāṁ viśālōpacitastanīm||16||
āliṅgyāgurudigdhāṅgīṁ supyāt samadamanmathaḥ| prakāmaṁ ca niṣēvēta maithunaṁ śiśirāgamē||17||
gurUShNavAsA digdhA~ggo guruNA~aguruNA sadA| shayane pramadAM pInAM vishAlopacitastanIm||16||
Ali~ggyAgurudigdhA~ggIM supyAt samadamanmathaH| prakAmaM ca niSheveta maithunaM shishirAgame||17||
In the winter season, one should always wear thick and warm clothes and the body should be anointed with thick paste of aguru (Aquilaria agallocha Roxb) (eagle-wood). A man who has taken alcohol and possesses strong passion should sleep in the bed at night embracing a healthy woman having well developed, plump breasts and herself anointed with the paste of aguru. One may indeed indulge in sexual intercourse up to full satisfaction. [16-17]
वर्जयेदन्नपानानि वातलानि लघूनि च| प्रवातं प्रमिताहारमुदमन्थं हिमागमे||१८||
varjayēdannapānāni vātalāni laghūni ca| pravātaṁ pramitāhāramudamanthaṁ himāgamē||18||
varjayedannapAnAni vAtalAni laghUni ca| pravAtaM pramitAhAramudamanthaM himAgame||18||
At the advent of winter season intake of food and drinks that are vata vitiating and light in nature, (getting exposed to) strong winds, inadequate quantities of food, and intake of diluted gruel are contraindicated. 
हेमन्तशिशिरौ तुल्यौ शिशिरेऽल्पं विशेषणम्| रौक्ष्यमादानजं शीतं मेघमारुतवर्षजम्||१९||
hēmantaśiśirau tulyau śiśirē'lpaṁ viśēṣaṇam| raukṣyamādānajaṁ śītaṁ mēghamārutavarṣajam||19||
hemantashishirau tulyau shishire~alpaM visheShaNam| raukShyamAdAnajaM shItaM meghamArutavarShajam||19||
Hemanta and shishira seasons are almost similar in characteristics with some specific features in shishra ritu. In this season, due to the onset of adana kala, dryness increases and due to clouds, winds and rain, cold prevails. 
तस्माद्धैमन्तिकः सर्वः शिशिरे विधिरिष्यते| निवातमुष्णं त्वधिकं शिशिरे गृहमाश्रयेत्||२०||
tasmāddhaimantikaḥ sarvaḥ śiśirē vidhiriṣyatē| nivātamuṣṇaṁ tvadhikaṁ śiśirē gr̥hamāśrayēt||20||
tasmAddhaimantikaH sarvaH shishire vidhiriShyate| nivAtamuShNaM tvadhikaM shishire gRuhamAshrayet||20||
Therefore, the whole regimen advised for hemanta should also be followed in shishira ritu. Along with this, one should specially stay in less windy and warm shelters (homes). 
कटुतिक्तकषायाणि वातलानि लघूनि च| वर्जयेदन्नपानानि शिशिरे शीतलानि च||२१||]
kaṭutiktakaṣāyāṇi vātalāni laghūni ca| varjayēdannapānāni śiśirē śītalāni ca||21||
kaTutiktakaShAyANi vAtalAni laghUni ca| varjayedannapAnAni shishire shItalAni ca||21||
In the shishiraseason, food and drinks that are predominantly pungent, bitter and astringent in taste, vata vitiating, and light and cold in nature should be avoided. 
Diet and lifestyle guidelines in vasanta ritu (spring season)
वसन्ते निचितः श्लेष्मा दिनकृद्भाभिरीरितः| कायाग्निं बाधते रोगांस्ततः प्रकुरुते बहून्||२२||
vasantē nicitaḥ ślēṣmā dinakr̥dbhābhirīritaḥ| kāyāgniṁ bādhatē rōgāṁstataḥ prakurutē bahūn||22||
vasante nicitaH shleShmA dinakRudbhAbhirIritaH| kAyAgniM bAdhate rogAMstataH prakurute bahUn||22||
Shleshma (kapha) accumulated in hemanta ritu gets liquefied by hot rays of the sun in vasanta ritu, which in turn disturbs/decreases the digestive power and ultimately causes many diseases. 
तस्माद्वसन्ते कर्माणि वमनादीनि कारयेत्| गुर्वम्लस्निग्धमधुरं दिवास्वप्नं च वर्जयेत्||२३||
tasmādvasantē karmāṇi vamanādīni kārayēt| gurvamlasnigdhamadhuraṁ divāsvapnaṁ ca varjayēt||23||
tasmAdvasante karmANi vamanAdIni kArayet| gurvamlasnigdhamadhuraM divAsvapnaM ca varjayet||23||
Therefore in vasanta season the purification procedures like vamana (emesis) and others should be done. One should avoid heavy, sour, unctuous and sweet food items and should not sleep during the daytime. 
व्यायामोद्वर्तनं धूमं कवलग्रहमञ्जनम्| सुखाम्बुना शौचविधिं शीलयेत् कुसुमागमे||२४||
vyāyāmōdvartanaṁ dhūmaṁ kavalagrahamañjanam| sukhāmbunā śaucavidhiṁ śīlayēt kusumāgamē||24||
vyAyAmodvartanaM dhUmaM kavalagrahama~jjanam| sukhAmbunA shaucavidhiM shIlayet kusumAgame||24||
In kusumagama kala (at the advent of spring) when flowers blossom (vasanta) one should regularly resort to physical exercise, dry massage, medicated smoking, gargling, and collyrium. Bathing and cleaning of excretory orifices should be done with lukewarm water. 
चन्दनागुरुदिग्धाङ्गो यवगोधूमभोजनः| शारभं शाशमैणेयं मांसं लावकपिञ्जलम्||२५||
candanāgurudigdhāṅgō yavagōdhūmabhōjanaḥ| śārabhaṁ śāśamaiṇēyaṁ māṁsaṁ lāvakapiñjalam||25||
candanAgurudigdhA~ggo yavagodhUmabhojanaH| shArabhaM shAshamaiNeyaM mAMsaM lAvakapi~jjalam||25||
A person should apply the paste of chandana (Santalum album Linn) and aguru on the body. One should take food made up of barley and wheat, meat of sarabha (wapiti), sasa (rabbit), ena (antelope), lava (common quail) and kapinjala (grey partridge). 
भक्षयेन्निर्गदं सीधुं पिबेन्माध्वीकमेव वा| वसन्तेऽनुभवेत् स्त्रीणां काननानां च यौवनम्||२६||
bhakṣayēnnirgadaṁ sīdhuṁ pibēnmādhvīkamēva vā| vasantē'nubhavēt strīṇāṁ kānanānāṁ ca yauvanam||26||
bhakShayennirgadaM sIdhuM pibenmAdhvIkameva vA| vasante~anubhavet strINAM kAnanAnAM ca yauvanam||26||
One should drink clean alcoholic drinks like sidhu and madhvika (types of wine preparations) in vasanta and enjoy the youthfulness of women and of gardens. 
Diet and lifestyle guidelines in grishma ritu (summer season)
मयूखैर्जगतः स्नेहं ग्रीष्मे पेपीयते रविः| स्वादु शीतं द्रवं स्निग्धमन्नपानं तदा हितम्||२७||
mayūkhairjagataḥ snēhaṁ grīṣmē pēpīyatē raviḥ| svādu śītaṁ dravaṁ snigdhamannapānaṁ tadā hitam||27||
mayUkhairjagataH snehaM grIShme pepIyate raviH| svAdu shItaM dravaM snigdhamannapAnaM tadA hitam||27||
In grishma ritu (summer season), the Sun , by its rays, excessively dries up the environment. So, in this season food and drinks having sweet, cold, liquid and unctuous qualities are considered wholesome. 
शीतं सशर्करं मन्थं जाङ्गलान्मृगपक्षिणः| घृतं पयः सशाल्यन्नं भजन् ग्रीष्मे न सीदति||२८||
śītaṁ saśarkaraṁ manthaṁ jāṅgalānmr̥gapakṣiṇaḥ| ghr̥taṁ payaḥ saśālyannaṁ bhajan grīṣmē na sīdati||28||
shItaM sasharkaraM manthaM jA~ggalAnmRugapakShiNaH| ghRutaM payaH sashAlyannaM bhajan grIShme na sIdati||28||
In the summer season, any individual taking cold and sweet mantha (a type of groat), meat of wild animals and birds, ghee and milk with shali rice (Oryza sativa Linn) does not become weak (i.e.,does not suffer from diseases). 
मद्यमल्पं न वा पेयमथवा सुबहूदकम्| लवणाम्लकटूष्णानि व्यायामं च विवर्जयेत् ||२९||
Madyamalpaṁ na vā pēyamathavā subahūdakam| lavaṇāmlakaṭūṣṇāni vyāyāmaṁ ca vivarjayēt ||29||
madyamalpaM na vA peyamathavA subahUdakam| lavaNAmlakaTUShNAni vyAyAmaM ca vivarjayet ||29||
Alcohol should be consumed in little quantities or should not be consumed at all, or if taken, should be diluted with plenty of water. One should stop taking salty, sour, pungent and hot food, and physical exercise should be avoided. 
दिवा शीतगृहे निद्रां निशि चन्द्रांशुशीतले| भजेच्चन्दनदिग्धाङ्गः प्रवाते हर्म्यमस्तके||३०||
Divā śītagr̥hē nidrāṁ niśi candrāṁśuśītalē| bhajēccandanadigdhāṅgaḥ pravātē harmyamastakē||30||
divA shItagRuhe nidrAM nishi candrAMshushItale| bhajeccandanadigdhA~ggaH pravAte harmyamastake||30||
During daytime, one should sleep in a cool shelter and during night after applying the paste of chandana (Santalum album Linn) on the body sleep in the airy roof/terrace of the house which is cooled by the Moon-rays. 
व्यजनैः पाणिसंस्पर्शैश्चन्दनोदकशीतलैः| सेव्यमानो भजेदास्यां मुक्तामणिविभूषितः||३१||
Vyajanaiḥ pāṇisaṁsparśaiścandanōdakaśītalaiḥ| sēvyamānō bhajēdāsyāṁ muktāmaṇivibhūṣitaḥ||31||
vyajanaiH pANisaMsparshaishcandanodakashItalaiH| sevyamAno bhajedAsyAM muktAmaNivibhUShitaH||31||
One should be seated on a surface decorated with pearl and gems and make use of a fan and touching by soft hands, both cooled with sandal water. 
काननानि च शीतानि जलानि कुसुमानि च| ग्रीष्मकाले निषेवेत मैथुनाद्विरतो नरः||३२||
Kānanāni ca śītāni jalāni kusumāni ca| grīṣmakālē niṣēvēta maithunādviratō naraḥ||32||
kAnanAni ca shItAni jalAni kusumAni ca| grIShmakAle niSheveta maithunAdvirato naraH||32||
In Summer, one should enjoy the coolness of gardens, cold water and flowers, and should abstain from sexual intercourse. 
Diet and lifestyle guidelines in varsha ritu (rainy season)
आदानदुर्बले देहे पक्ता भवति दुर्बलः| स वर्षास्वनिलादीनां दूषणैर्बाध्यते पुनः||३३||
ādānadurbalē dēhē paktā bhavati durbalaḥ| sa varṣāsvanilādīnāṁ dūṣaṇairbādhyatē punaḥ||33||
AdAnadurbale dehe paktA bhavati durbalaH| sa varShAsvanilAdInAM dUShaNairbAdhyate punaH||33||
In a weak body, during the period of dehydration, agni is also weak, and deteriorates further due to vitiated vata and other doshas during rainy season. 
भूबाष्पान्मेघनिस्यन्दात् पाकादम्लाज्जलस्य च| वर्षास्वग्निबले क्षीणे कुप्यन्ति पवनादयः||३४||
bhūbāṣpānmēghanisyandāt pākādamlājjalasya ca| varṣāsvagnibalē kṣīṇē kupyanti pavanādayaḥ||34||
bhUbAShpAnmeghanisyandAt pAkAdamlAjjalasya ca| varShAsvagnibale kShINe kupyanti pavanAdayaH||34||
In this season, due to evaporating vapors from the Earth, rainfall and acidic transformation of water, the agni is weakened, thus leading to the further vitiation of vata and other doshas. 
तस्मात् साधारणः सर्वो विधिर्वर्षासु शस्यते| उदमन्थं दिवास्वप्नमवश्यायं नदीजलम्||३५||
व्यायाममातपं चैव व्यवायं चात्र वर्जयेत्| पानभोजनसंस्कारान् प्रायः क्षौद्रान्वितान् भजेत्||३६||
tasmāt sādhāraṇaḥ sarvō vidhirvarṣāsu śasyatē| udamanthaṁ divāsvapnamavaśyāyaṁ nadījalam||35||
vyāyāmamātapaṁ caiva vyavāyaṁ cātra varjayēt| pānabhōjanasaṁskārān prāyaḥ kṣaudrānvitān bhajēt||36||
tasmAt sAdhAraNaH sarvo vidhirvarShAsu shasyate| udamanthaM divAsvapnamavashyAyaM nadIjalam||35||
vyAyAmamAtapaM caiva vyavAyaM cAtra varjayet| pAnabhojanasaMskArAn prAyaH kShaudrAnvitAn bhajet||36||
Hence, in rainy season all basic rules regarding diet and behavior are advised to balance all three doshas. One should avoid diluted mantha (groat), sleeping during the day, dew, river water, physical exercise, exposure to sun rays and sexual intercourse in this season. One should use food and drinks mostly added with honey in small quantity to pacify the kleda (dampness) of rainy season. [35-36]
व्यक्ताम्ललवणस्नेहं वातवर्षाकुलेऽहनि| विशेषशीते भोक्तव्यं वर्षास्वनिलशान्तये||३७||
vyaktāmlalavaṇasnēhaṁ vātavarṣākulē'hani| viśēṣaśītē bhōktavyaṁ varṣāsvanilaśāntayē||37||
vyaktAmlalavaNasnehaM vAtavarShAkule~ahani| visheShashIte bhoktavyaM varShAsvanilashAntaye||37||
In the rainy season when the days are cooler due to wind and rain, one should predominantly take sour, salty and unctuous food to alleviate vata. 
अग्निसंरक्षणवता यवगोधूमशालयः| पुराणा जाङ्गलैर्मांसैर्भोज्या यूषैश्च संस्कृतैः||३८||
agnisaṁrakṣaṇavatā yavagōdhūmaśālayaḥ| purāṇā jāṅgalairmāṁsairbhōjyā yūṣaiśca saṁskr̥taiḥ||38||
agnisaMrakShaNavatA yavagodhUmashAlayaH| purANA jA~ggalairmAMsairbhojyA yUShaishca saMskRutaiH||38||
A person taking care of his agni should consume old barley; wheat and shali rice (Oryza sativa Linn) along with meat of wild animals and processed soup. 
पिबेत् क्षौद्रान्वितं चाल्पं माध्वीकारिष्टमम्बु वा| माहेन्द्रं तप्तशीतं वा कौपं सारसमेव वा||३९||
pibēt kṣaudrānvitaṁ cālpaṁ mādhvīkāriṣṭamambu vā| māhēndraṁ taptaśītaṁ vā kaupaṁ sārasamēva vā||39||
pibet kShaudrAnvitaM cAlpaM mAdhvIkAriShTamambu vA| mAhendraM taptashItaM vA kaupaM sArasameva vA||39||
Whenever madhvika or other fermented liquors and water are consumed, they should be mixed with a little amount of honey. Rain water or water from wells or ponds should be properly boiled and cooled. 
प्रघर्षोद्वर्तनस्नानगन्धमाल्यपरो भवेत्| लघुशुद्धाम्बरः स्थानं भजेदक्लेदि वार्षिकम्||४०||
pragharṣōdvartanasnānagandhamālyaparō bhavēt| laghuśuddhāmbaraḥ sthānaṁ bhajēdaklēdi vārṣikam||40||
pragharShodvartanasnAnagandhamAlyaparo bhavet| laghushuddhAmbaraH sthAnaM bhajedakledi vArShikam||40||
In the rainy season, one should practice friction massage, dry massage, bathing, use of fragrance, garlands, wear light and clean clothes and should reside in the place which is free from humidity. 
Diet and lifestyle guidelines in sharada ritu (autumn season)
वर्षाशीतोचिताङ्गानां सहसैवार्करश्मिभिः| तप्तानामाचितं पित्तं प्रायः शरदि कुप्यति||४१||
varṣāśītōcitāṅgānāṁ sahasaivārkaraśmibhiḥ| taptānāmācitaṁ pittaṁ prāyaḥ śaradi kupyati||41||
varShAshItocitA~ggAnAM sahasaivArkarashmibhiH| taptAnAmAcitaM pittaM prAyaH sharadi kupyati||41||
When a body habituated to cold and rain is suddenly subjected to the heat of sun-rays in the sharada season, the accumulated pitta in the body often gets aggravated. 
तत्रान्नपानं मधुरं लघु शीतं सतिक्तकम्| पित्तप्रशमनं सेव्यं मात्रया सुप्रकाङ्क्षितैः||४२||
tatrānnapānaṁ madhuraṁ laghu śītaṁ satiktakam| pittapraśamanaṁ sēvyaṁ mātrayā suprakāṅkṣitaiḥ||42||
tatrAnnapAnaM madhuraM laghu shItaM satiktakam| pittaprashamanaM sevyaM mAtrayA suprakA~gkShitaiH||42||
In this season food and drinks predominantly of sweet, light, cold and slightly bitter qualities and having pitta alleviating properties should be taken in proper quantity, only when there is good appetite. 
लावान् कपिञ्जलानेणानुरभ्राञ्छरभान् शशान्| शालीन् सयवगोधूमान् सेव्यानाहुर्घनात्यये||४३||
lāvān kapiñjalānēṇānurabhrāñcharabhān śaśān| śālīn sayavagōdhūmān sēvyānāhurghanātyayē||43||
lAvAn kapi~jjalAneNAnurabhrA~jcharabhAn shashAn| shAlIn sayavagodhUmAn sevyAnAhurghanAtyaye||43||
In ghanatyaya (sharada ritu) the meat of lava (common quail), kapinjala (grey partridge), ena (antelope), urabhra (sheep), sarabha (wapiti) and shasha (rabbit), shali rice (Oryza sativa Linn), barley and wheat should be taken. 
तिक्तस्य सर्पिषः पानं विरेको रक्तमोक्षणम्| धाराधरात्यये कार्यमातपस्य च वर्जनम्||४४||
tiktasya sarpiṣaḥ pānaṁ virēkō raktamōkṣaṇam| dhārādharātyayē kāryamātapasya ca varjanam||44||
tiktasya sarpiShaH pAnaM vireko raktamokShaNam| dhArAdharAtyaye kAryamAtapasya ca varjanam||44||
In sharada, whenever the rain clouds disappear (dharadharatyaye), the intake of ghee medicated with bitter items, use of purgatives, and blood-letting are indicated. 
वसां तैलमवश्यायमौदकानूपमामिषम्| क्षारं दधि दिवास्वप्नं प्राग्वातं चात्र वर्जयेत्||४५|| vasāṁ tailamavaśyāyamaudakānūpamāmiṣam| kṣāraṁ dadhi divāsvapnaṁ prāgvātaṁ cātra varjayēt||45|| vasAM tailamavashyAyamaudakAnUpamAmiSham| kShAraM dadhi divAsvapnaM prAgvAtaM cAtra varjayet||45||
In this season exposure to Sun, intake of fats and oils, exposure to dew, meat of aquatic and marshy animals, alkaline preparations, and curd are contraindicated. One should not sleep during daytime and restrict exposure to easterly wind. 
दिवा सूर्यांशुसन्तप्तं निशि चन्द्रांशुशीतलम्| कालेन पक्वं निर्दोषमगस्त्येनाविषीकृतम्||४६||
हंसोदकमिति ख्यातं शारदं विमलं शुचि| स्नानपानावगाहेषु हितमम्बु यथाऽमृतम् ||४७|
Divā sūryāṁśusantaptaṁ niśi candrāṁśuśītalam| kālēna pakvaṁ nirdōṣamagastyēnāviṣīkr̥tam||46||
haṁsōdakamiti khyātaṁ śāradaṁ vimalaṁ śuci| snānapānāvagāhēṣu hitamambu yathā'mr̥tam ||47||
divA sUryAMshusantaptaM nishi candrAMshushItalam| kAlena pakvaM nirdoShamagastyenAviShIkRutam||46||
haMsodakamiti khyAtaM shAradaM vimalaM shuci| snAnapAnAvagAheShu hitamambu yathA~amRutam ||47||
Water heated with sunrays during daytime and cooled with moon rays during night, well purified by the course of time and detoxified by the effects of Agastya (the star Canopus) is called Hansodaka, which is available during sharada and is clean and clear. This water is beneficial as nectar when used for the purpose of bathing and drinking. [46-47]
शारदानि च माल्यानि वासांसि विमलानि च| शरत्काले प्रशस्यन्ते प्रदोषे चेन्दुरश्मयः||४८||
śāradāni ca mālyāni vāsāṁsi vimalāni ca| śaratkālē praśasyantē pradōṣē cēnduraśmayaḥ||48||
shAradAni ca mAlyAni vAsAMsi vimalAni ca| sharatkAle prashasyante pradoShe cendurashmayaH||48||
In sharada ritu, garlands of seasonal flowers, clean clothes (apparels), and exposure to moon-rays in early nights are very beneficial. 
Okasatmya(acquired adaptation or habituation)
इत्युक्तमृतुसात्म्यं यच्चेष्टाहारव्यपाश्रयम्| उपशेते यदौचित्यादोकःसात्म्यं तदुच्यते||४९||
ityuktamr̥tusātmyaṁ yaccēṣṭāhāravyapāśrayam| upaśētē yadaucityādōkaḥsātmyaṁtaducyatē||49||
ityuktamRutusAtmyaM yacceShTAhAravyapAshrayam| upashete yadaucityAdokaHsAtmyaM taducyate||49||
In this way, we discussed about seasonal adaptations with respect to activities and diet.
If any diet and behavior become suitable to the body by its regular/habitual use then it is called okasatmya (acquired adaptation or habituation). 
देशानामामयानां च विपरीतगुणं गुणैः| सात्म्यमिच्छन्ति सात्म्यज्ञाश्चेष्टितं चाद्यमेव च||५०||
dēśānāmāmayānāṁ ca viparītaguṇaṁ guṇaiḥ| sātmyamicchanti sātmyajñāścēṣṭitaṁ cādyamēva ca||50||
deshAnAmAmayAnAM ca viparItaguNaM guNaiH| sAtmyamicchanti sAtmyaj~jAshceShTitaM cAdyameva ca||50||
Experts of the principles of satmya (adaptation) consider that diet and behavior opposite to the qualities of the habitat of the individual and of the causative factors of the diseases prevalent in the location, can be adapted to. 
ऋतावृतौ नृभिः सेव्यमसेव्यं यच्च किञ्चन| तस्याशितीये निर्दिष्टं हेतुमत् सात्म्यमेव च||५१||
tatra ślōkaḥ- Rtāvr̥tau nr̥bhiḥ sēvyamasēvyaṁ yacca kiñcana| tasyāśitīyē nirdiṣṭaṁ hētumat sātmyamēva ca||51||
tatra shlokaH- RutAvRutau nRubhiH sevyamasevyaM yacca ki~jcana| tasyAshitIye nirdiShTaM hetumat sAtmyameva ca||51||
There is the verse: In this chapter of “One’s Diet”, general principles with respect to dietary habits and activities suitable to specific seasons, along with the principles of satmya (adaptation) have been described. 
इत्यग्निवेशकृते तन्त्रे चरकप्रतिसंस्कृते श्लोकस्थाने तस्याशितीयो नाम षष्ठोऽध्यायः||६||
Ityagnivēśakr̥tē tantrē carakapratisaṁskr̥tē ślōkasthānē tasyāśitīyō nāma ṣaṣṭhō'dhyāyaḥ||6||
- The strength of a person varies according to seasonal changes. The doshas undergo physiological variations as per change in season. In order to maintain equilibrium and sustain health, a person should change his diet and lifestyle according to the season.
- Human beings function like a microcosm of the universe and the physiological changes are predominantly affected by the changes in macrocosm e.g, geothermal changes due to the Sun or the effects of the Moon and other celestial bodies. The rotation of the Earth around the Sun and rotation of Moon around the Earth result in changes in season. The Sun is responsible for temperature variations on Earth and this leads to changes in the physical and mental strength of a microcosm.
The effect of seasonal variations on an individual’s physiological strength are as follows:
|Ayana||Ritu||Indian Months||English Months||Strength|
|Samvatsara||Uttarayana||Shishira (Late Winter)||Magha(Tapa) and Phalguna(Tapasya)||Mid-Jan to Mid-March||Good|
|Vasanta (Spring)||Chaitra(Madhu) and Vaishaka(Madhava)||Mid-March to Mid-May||Medium|
|Grishma (Summer)||Jaishtha(Shuchi) and Ashadha(Shukra)||Mid-May to Mid-July||Weak|
|Dakshinayana||Varsha (Rainy Season)||Shravana(Nabha) and Bhadrapada(Nabhasya)||Mid-July to Mid-Sep||Weak|
|Sharada (Autumn)||Ashvina(Isha) and Kartika(Urja)||Mid-Sep to Mid-Nov||Medium|
|Hemanta (Early Winter)||Margashirsha(Saha) and Pausha(Sahasya)||Mid-Nov to Mid-Jan||Good|
These effects of seasonal variations on bala should be factored in while planning any dietary or preventive healthcare program for any individual.
- The stages of dosha as per seasonal changes are as follows:
|Dosha||Sanchaya(Accumulation)||Prakopa(Aggravation)||Prashamana(Pacification to Normalcy)|
|Vata||Grishma (Summer)||Varsha (Monsoon/Rainy)||Sharada (Autumn)|
|Pitta||Varsha (Monsoon/Rainy)||Sharada (Autumn)||Hemanta (Early Winter)|
|Kapha||Shishira (Late Winter)||Vasanta (Spring)||Grishma (Summer)|
- One should follow the diet and lifestyle with opposite properties of the place of residence and seasons in order to preserve health and prevent diseases.
Division of samvatsara (year) and ritus
The Year or Samvatsara is divided into two ayana or solstices, depending upon the position of the Sun with respect to the Earth i.e. Uttarayana or adana kala and dakshinayana or visarga kala. Each ayana includes three ritus. This is known as ritu cycle of six seasons. Six ritus are divided on the basis of the predominant effect of Sun and Moon. Air motivates the Sun and the Moon. Vata is responsible for differentiation of ritus.The uttarayana or northward position of the Sun and its act of dehydration/undernourishment brings about three seasons, including shishira, vasanta and grishma. The dakshinayana or southward position of the Sun and its act of hydration/nourishment gives rise to other three seasons, including varsha, sharada and hemanta.
Per Ayurvedic literature, taking the river Ganga as a baseline, the whole region (India) is divided on the basis of intensity of cold and rain into two parts. In regions south of Ganga, rain being more, two ritu i.e. pravrita and varsha (early rainy and heavy rainy seasons) have been mentioned separately by the sages. In the regions north of Ganga, with a prevalence of snowfall factored in, two ritu namely hemanta and shishira (dewy season and cold season) have been mentioned separately. In the Gangetic plains (Eastern U.P. and Bihar), all the seasons can be found since it is the belt of Sadharana desha.
Thus in Ayurveda, a year is divided in two ways on the basis of the following:
Seasonal regimen for Healthy Living
|Ayana||Ritu||Indian Months||Influential Rashi||English Months|
|Samvatsara||Uttarayana||Shishira (Late Winter)||Magha(Tapa) and Phalguna(Tapasya)||Makara and Kumbha||Mid-Jan to Mid-March|
|Vasanta (Spring)||Chaitra(Madhu) and Vaishaka(Madhava)||Meena and Mesha||Mid-March to Mid-May|
|Grishma (Summer)||Jaishtha(Shuchi) and Ashadha(Shukra)||Vrishabha and Mithuna||Mid-May to Mid-July|
|Dakshinayana||Varsha (Rainy Season)||Shravana(Nabha) and Bhadrapada(Nabhasya)||Karka and Simha||Mid-July to Mid-Sep|
|Sharada (Autumn)||Ashvina(Isha) and Kartika(Urja)||Kanya and Tula||Mid-Sep to Mid-Nov|
|Hemanta (Early Winter)||Margasirsha(Saha) and Pausha(Sahasya)||Vrishchika and Dhanu||Mid-Nov to Mid-Jan|
Characteristics of seasons
|Character||Ritu||Indian Months||English Months|
|Samvatsara||Cold, Hot, Wet(Rainy)||Hemanta (Early Winter)||Pausha and Magha||Mid-Dec to Mid-Feb|
|Grishma (Summer)||Vaishaka and Jaishtha||Mid-April to Mid-June|
|Varsha (Monsoon/Rainy)||Bhadrapada and Ashvina||Mid-Aug to Mid-Oct|
|Moderate||Vasanta (Spring)||Phalguna and Chaitra||Mid-Feb to Mid-Apr|
|Pravrita (Early Rains)||Ashadha and Shravana||Mid-Jun to Mid-Aug|
|Sharada (Autumn)||Kartika and Margashirsha||Mid-Oct to Mid-Dec|
Formation of Seasons
The Earth and all other celestial bodies in the Solar System are constantly moving. Rotation, precession and revolution of Earth are directly responsible for seasonal variations in a year. The term ‘Earth Rotation’ refers to the spinning of our planet on its axis, with an equatorial speed of 1040 miles per hour (about 465 meter per second or slightly over 1675 km per hour). One rotation takes twenty-four hours (23.93 hour) and is called a mean solar day. The Earth’s rotation is responsible for the daily cycles of day and night. At any moment in time, one half of the Earth is in sunlight, while the other half is in darkness. The Earth's rotation axis is not fixed in the space. The direction of the rotation axis executes a slow ‘Precession’, caused by the gravitational pull of the Sun and the Moon on the Earth. Through each 26 000-year cycle, the direction in the sky to which the axis points goes around a big circle, the radius of which covers an angle of about 23.50. This precession also has an effect on the seasons. The orbit of the Earth around the Sun is called an ‘Earth Revolution’. This celestial motion takes 365.26 days to complete one cycle. Further, the Earth's orbit around the Sun is not circular, but oval or elliptical. An elliptical orbit causes the Earth's distance from the Sun to vary over a year.
The solstices, together with the equinox, are connected with the seasons. They are considered to start or separate the seasons, or fall nearer the middle. A solstice is an astronomical event that happens twice each year when the Sun’s apparent position in the sky, as viewed from Earth, reaches its northernmost or southernmost extremes. This usually happens around June 21st and December 21st. An equinox occurs twice a year, when the tilt of the Earth’s axis is inclined neither away from nor towards the Sun, the center of the Sun being in the same plane as the Earth's equator. Around the equinox, the night and day have approximately equal length and the rays of the Sun shine directly on the equator. This happens on approximately March 20th and September 22nd. The Indian Meteorological Department (IMD) designates four different seasons – winter, summer or pre-monsoon, monsoon or rainy season, and post-monsoon season.
Qualities of seasons
The qualities of different seasons are to be understood in three aspects viz. masa (month), rashi (stellar constellations) and svarupa (characteristic features). The regimen prescribed for each seasons should be followed in mild, moderate or full degree in the succeeding order of strength of seasons. Importance is given first to the appearance of svarupa in reckoning season, then to the rashi and last to the masa. The regimen prescribed for the seasons should be mild or part, if only masa has commenced without commencement of rashi or svarupa; it should be moderate if rashi has commenced but svarupa has not yet; and regimen should in full measure if svarupa has commenced ever without rashi.
The characteristics of normal seasons have been described in terms of various environmental factors. Knowledge of these characteristics is important to differentiate between deranged (abnormal) and normal seasons so that precautions can be taken to prevent the adverse effect of abnormal seasons.
Importance of ritucharya
One’s various type of diet leads to promotion of strength and luster only when he knows the wholesomeness according to different seasons dependent on behavior and diet.
A man always becomes healthy only when he properly follows dinacharya (day routine), nishacharya (night routine) and ritucharya (seasonal routine) otherwise he will have disease.
Basic principles of ritucharya
- While passing through six seasons our body is bound to face different variations and accordingly it is likely to get affected if the same routine is followed in all seasons.
- The basic principle of ritucharya is to preserve the equilibrium of dosha through the concept of samanya and vishesha.
- Knowledge and regular observance of suitable ritucharya (ahara and vihara for different seasons) is mainly for the maintenance of health and prevention of diseases. For diseased persons ritucharya has to be modified accordingly.
- The seasons are differentiated according to month, rashi and characteristics. More importance has been given to the appearance of characteristics.
- Every person should take diet including all the six rasa (tastes), in each and every season; however, the indicated rasa should be taken in predominant quantity in particular season. Regular intake of all rasa is best strength promoter and regular use of any one rasa debilitates strength.
- Follow the regimen carefully during ritusandhi and yamadamshtra period to live healthy.
Dosha - rasa relationship
Different rasas present in our food have a direct effect on three doshas. Madhura, amla and lavana rasa alleviate vata and aggravate kapha dosha. Tikta, katu and kashya rasa alleviate kapha and aggravate vata. Pitta dosha get alleviated by kashya, tikta and madhura rasa, where as pitta aggravating rasa are amla, lavana, and katu.
Concept of ritu sandhi
The last seven days of preceding ritu and first seven days of following ritu are together known as ritusandhi (meeting of two seasons). During this period the regimen of the previous season should be discontinued gradually and those of the succeeding season adopted slowly. Particular padamshika krama has to be adopted i.e. Unhealthy things which one has become accustomed should be discontinued gradually (quarter by quarter, say). Similarly healthy things (food etc) should be made use of (gradually) with intervals of one, two or three days. On the other hand, if they are discontinued or adopted suddenly, diseases due to unaccustomed foods and activities develop. It is a significant advice, as the changeover of external environment from one season to other is very rapid, but our endogenous system needs some time for smooth change over.
The duration of last eight days of Kartika and first eight days of Magha is termed as yamadamshtra. It is advised to take little food during this period for healthy living otherwise it may be fatal.
Concept of satmya and okasatmya
Satmya means any substance or behavior which is suitable and beneficial to the self. Satmya being used constantly has wholesome effect. It is divided into two types:
- Prakritisatmya is also called as ajanmasatmya i.e. the satmya since birth, like madhura rasa.
- Abhyasasatmya includes four types of satmya, i.e. vyadhisatmya, deshasatmya, okasatmya and ritusatmya.
- Vyadhisatmya: Adaptation to a disease. There are things which cannot be taken in normal health but have to be tolerated during the period when a person falls sick. It is also called amayasatmya or rogasatmya.
- Deshasatmya: Adaptation to locality or country. There are many things which may be used constantly at a particular place in a particular time but may not be in practice at a different place in same time.
- Okasatmya: Acquired adaptation. Anything such as a poisonous or an intoxicating thing or habit which if resorted to is capable of producing deleterious or injurious effect upon ones health. If taken bit by bit, by an individual continuously it loses its grip to produce deleterious or injurious effect and keeps the individual in normal health, it then becomes okasatmya to the user. This is not only true for poisonous things. Sometimes particular way of living is injurious to one’s health in a particular season but if continues that habit it will lose its power to produce harmful effect. This is one of the reason why all the individuals not affected by seasonal diseases in spite of not following seasonal regimen.
- Ritusatmya: Seasonal adaptation has been described in the ritucharya (seasonal regimen), which is dependent upon ahara (food articles) and vihara (behavior).
Charya / Characteristics of different Seasons
Hemanta ritucharya (Regimen for Early winter)
|Ahara (diet)||Vihara (regimen)|
|Grahya||Amla(sour), Lavana(salty), Madhura(sweet), Guru (heavy in digestion) and Snigdha dravya(unctuous food), new rice and wheat, fats and oils, black gram and its products, milk and its products, sugarcane products, warm water, honey, anupa (animals of marshy land) and audaka mansa (meat of aquatic animals), liquor||protection from cold by warm clothes and beddings, Living in warm house, regular use of shoes, bathing with warm water, abhyanga (oil massage), utsadana (powder massage), vyayama ( physical exercise), atapa sevana(exposing body to sun light), intercourse|
|Varjya||Laghu (light in digestion) and vatala dravya, pramitahara(frequently taking food), udamantha( groat)||Divasvapna (sleeping in day time), direct air|
Shishira ritucharya (Regimen for Late winter)
Hemanta and shishira are similar with the slight difference in that the latter has more roughness due to beginning of Adana and cold due to clouds, winds and rains. Hence the entire routine of living prescribed for Hemanta is to be followed in Shishira also. During Shishira, one should specially live in warmer settings and protect oneself from direct air. Avoid katu, tikta, kashaya, laghu, sheeta and vatala food and drinks.
Vasanta ritucharya (Regimen for Spring)
|Ahara (diet)||Vihara (regimen)|
|Grahya||food articles having taste like katu(pungent), tikta(bitter) and kasaya(astringent), ruksha(ununctous), laghu (light in digestion) and ushna dravya(hot substances) , old wheat, rice and barley, water medicated with ginger, khadira(acasia catechu,Linn), Musta(cyperus rotundus Linn) and Honey; Jangala Mansa( meat of terrestrial animals), Liquor||kavala dharana(medicated gargling), anjana(application of collyrium), dhumapana(medicated smoking), vyayama, udvartana, chandana and aguru lepa, intercourse, vamana(emesis) and nasya(nasal medication)|
|Varjya||Madhura(sweet), amla(sour), guru( heavy in digestion), snigdha and sheeta(cold) dravya, curd||direct sunlight, divasvapna( day sleep), sleeping under dew|
Grishma ritucharya (Regimen for Summer)
|Ahara (diet)||Vihara (regimen)|
|Grahya||madhura, drava, sheeta, laghu and snigdha dravya, mantha with sugar, rice, ghee, milk, shali rice, Jangala Mansa (meat of terrestrial animals)||divasvapna, living and sleeping in cold place, protection from heat, bathing with cold water, chandana lepa, wearing of light clothes|
|Varjya||lavana, amla, katu and ushna dravya, curd, liquor||vyayama, atapa sevana, intercourse|
Varsha ritucharya (Regimen for Rainy season)
|Ahara (diet)||Vihara (regimen)|
|Grahya||madhura, amla, lavana, snigdha and ushna dravya, old wheat, rice and barley, gruel prepared with pulses, Food and drinks with honey, boiled and cold water, jangala mansa, liquor||living in dry place, wearing of light clothes, pragharshana, udvartana, basti, virechana, vamana, Use of flowers and perfume|
|Varjya||ruksha and ati-drava dravya (excessive water), udamantha (groat), river water||divasvapna (day sleep) vyayama (physical exercise) living under dew, eastern wind, excessive sunlight exposure, intercourse|
Sharada ritucharya (Regimen for Autumn)
|Ahara (diet)||Vihara (regimen)|
|Grahya||madhura(sweet), tikta(pungent) and kashya(astringent) dravya, laghu (light for digestion), ruksha(rough) and sheeta(cold) dravya, wheat, rice, barley and mudga (green gram), milk, sugar and sugarcane, tikta sarpi (ghee prepared out of bitter drugs), river water, Hansodaka, Jangala mansa(meat of arid animals)||virechana(medical purgation), raktamokshana (bloodletting), living under moon light, wearing of flowers, pearls, clean clothes|
|Varjya||amla(sour), katu (pungent), tikshana(sharp) and ushna(hot dry) dravya, kshara(alkaline preparations), oils and fat, curd, ginger, anupa (animals of marshy land) and audaka mansa (aquatic animals), liquor||divasvapna (day sleep), vyayama (physical exercise), eastern wind, living in dew, atapa sevana(exposing body to sun light)|
- Common Diseases due to Non-observance of ritucharya
Many diseases described in Ayurveda have their own peculiar causes to develop in particular season, like jwara, tamaka shvasa, pratishyaya, amlapitta, shirahshula, sandhi-shula, atisara, sheetapitta, kushtha etc.
- Jwara (fever) is of two types, viz., prakrita (natural) and vaikrita (unnatural) based on prognosis. On the basis of prakriti (nature) of time the fever is termed as prakrita (natural). Kaphaja jwara occurs in vasanta and pittaja in sharada (autumn), are known as prakrita (normal) and are easily curable, while vatika jwara in prakrita season (pravrita) is not easily curable. Fever occurs in seasons other than that responsible for vitiation of the concerned dosha is known as Vaikrita (unnatural) which is troublesome.
- Tamaka shvasa (bronchial asthma) is aggravated by cloudy, cold, rainy weather and easterly wind and kapha increasing factors. On the other hand warmth relieves the symptoms.
- Pratishyaya (rhinitis): Seasonal irregularity is one of the causative factors of pratishyaya. Thus pratishyaya can occur in any season if we do not follow seasonal regimen and especially in exposure to too much of cold.
- Amlapitta (acid peptic disorder) is prevalent in rainy season because of natural accumulation of pitta in rainy season. Indulgence in foods which are incompatible, spoiled, very sour, causing burning sensation in epigastrium cause increase of pitta to produce amlapitta, in persons in whom pitta has already increased.
- Shirahshula (headache) is a common feature of all types of shiroroga and is of three types:
- Vatika shiroroga:
- Aggravating factors: Cold season; Rainy season and cloudy days
- Relieving factors: Hot season, clear and shiny sky i.e. cloud free days
- Paittika shiroroga:
- Aggravating factors: Hot season, Intake of hot food
- Relieving factors: Cold season
- Kaphaja shiroroga:
- Aggravating factors: Vasanta season, cold season
- Relieving factors: Hot season
- Vatika shiroroga:
- Shula (pain)
- Vatika shula: Vatika shula especially gets exacerbated after digestion of food, in the evening time, at the end of night, during cloudy and rainy days, in cold climate, and due to direct and eastern wind exposure.  It gets relieved by swedana(sudation), abhyanga(oil massage), mardana(massage), unctuous, and hot food items. On the basis of site the vatika shula may be termed as janusandhigata shula (Osteo arthritis of knee), kati shula (low backache), prishthagata vatika shula(backache), and trikagata vatika shula (pain in pelvic region), etc.
- Paittika shula: It gets exacerbated during mid day, mid night, at the time of digestion of food, and during sharada ritu. It gets relieved by cold season, cold and madhura food.
- Kaphaja shula: This type of pain gets exacerbated just after intake of food, during early morning, at the beginning of night, and during shishira and vasanta seasons.
- Atisara (diarrhea): Rituviparyaya (any deviation from seasonal regimen) is the main cause of atisara .
- Sheetapitta (urticaria): Exposure to cold air aggravates kapha and vata dosha, and along with pitta cause sheetapitta. It increases during rainy and winter seasons and especially in shishira ritu.
- Kushtha (skin diseases): The first important cause of kushtha is viruddha anna-pana (intake of antagonistic food), which includes kala viruddha also for e.g. during hot season intake of katu and hot variety of foods and during cold season ruksha (rough) and sheeta (cold) foods are kala viruddha.
Effect of seasonal changes on health
Various researches have proved the direct relation of seasonal variation on physiological and pathological changes in body:
- Climate change has a profound effect on human health and well-being. The impact of climate change on human well-being goes beyond mortality; even birth rates and sperm counts appear to be affected by meteorological phenomenon.,  
- Morbidity attributed to pneumonia, influenza, bronchitis, and probably many other illnesses are also weather-related.
- Medical disorders such as bronchitis, peptic ulcer, adrenal ulcer, glaucoma, goiter, eczema, and herpes zoster are related to seasonal variations in temperature.
- A Canadian Climate Center study (1981) found that migraines were most likely to occur on days with falling pressure, rising humidity, high winds, and rapid temperature fluctuations.
- Weather has an important influence on morbidity in the winter because cold, dry air leads to excessive dehydration of nasal passages and upper respiratory tract, and increased chance of microbial and viral infection. In general, total mortality is about 15% higher on an average winter day than on an average summer day, according to National Center for Health Statistics, 1978.
- Mortality rate during heat waves increases with age.  The elderly seem to suffer from impaired physiological responses and often are unable to increase their cardiac output sufficiently during extremely hot weather.
- It was noted that men who had taken bath in 15oC water for one-half hour over nine consecutive days before a trip to the Arctic showed less signs of cold-induced stress than non-treated men. It indicates that adaptation to cold temperatures can occur through repeated exposures. 
- To a great extent, the seasonal changes in the immune system are controlled by changes in the levels of various hormones, particularly melatonin. Serum levels of melatonin were found to be highest in the winter months in both normal individuals and SLE patients. There is natural increase in bala (strength/immunity) of individuals during winter i.e. hemanta and shishira ritu.
- Striking seasonal variations have been demonstrated in the plasma and saliva levels of the glucocorticoid, cortisol, which promotes carbohydrate metabolism. The lowest levels of cortisol were found in healthy individuals during spring and summer, while the highest levels were found during autumn and winter seasons.
- Agni (digestive power) of individuals is strong during winter i.e. hemanta and shishira ritu, and weakest during grishma and varsha ritu.
- Rheumatic diseases vary in severity by season. The incidence of acute gouty attacks (an inflammatory arthritis) is highest in the spring season. Schlesinger N.et al. (2009) explained in his paper “Seasonal Variation of Rheumatic Diseases” that seasonal variation has been shown in a number of rheumatic diseases.
- Coronary artery disease shows a winter peak and summer trough in incidence and mortality. Leo Sher also proposed that seasonal mood changes may contribute to the increased incidence and mortality of coronary artery disease in winter. Depression is associated with increased incidence, morbidity, and mortality of coronary artery disease.
- “Seasonal affective disorder” is a condition where depression in the winter and fall alternate with non-depressive periods in the spring and summer. The degree to which seasonal changes affect mood, energy, sleep, appetite, food preference, or the wish to socialize with other people has been called "seasonality." Recent studies have demonstrated that seasonal mood changes are related to the genetic factors. It means that people may have genetically‐determined sensitivity to seasons.
- Jaiswal et al, 2011, in a clinical survey found a significant relation between seasonal variation and prevalence of some diseases viz. jwara (viral fever), amlapitta (acid peptic disorders), tamaka shvasa (bronchial asthma), pratishyaya (rhinitis) and sirashula (pittaja sirashula and ardhavabhedaka, migraine). They also observed that there is seasonal variation in the state of agni and bala strength) of the person, as stated by our ancient seers.
- Nathani et al, 2013, in a clinical research found that maximum number of patients of tamaka shvasa (bronchial asthma) were registered in winter seasons (hemanta and shishira), vasanta and varsha. These seasons were the predominant period of asthma attack in majority of cases. In maximum number of cases the attack of tamaka shvasa gets precipitated by intake of kapha and vata vitiating sheeta, guru, madhura and amla rasa predominant ahara like ice-cream, cold drink, cold water, fruit juices, curd, sweets, rice, pickle, salad with lemon etc. in all seasons.
- Ch.Su. 12
- S.Su. 6
- Ca.Su. 6/3
- Su.Ut. 64/55
- BhÁ. Pra. 5/356
- BhÁ. Pra. 5/13
- A.S.Su. 1/36
- C.Su. 7/36-37
- A.S.Su. 4/61
- Sh.Pu. 2/30
- A.H.Su. 10
- C.Ci. 3/42
- C.Ci. 26/104
- M.Ni. 51/1
- M.Ni. 26/4
- S.Su. 21/20
- M.Ni. 26/8
- M.Ni. 26/10
- S.Ut. 40/4
- M.Ni. 50/1
- C. Ci. 7/4-8
- Calot and Blayo, 1982
- Tjoa et al, 1982
- White and Hertz, 1985
- White et al, 1985
- Tromp, 1963
- Oechsli et al, 1970
- Buechley et al, 1972
- Sprung C.L., 1979
- Radomski and Boutelier, 1982
- Nelson et al., 2000
- Walker et al, 1997
- Schlesinger N et al., 1998
- Schlesinger N et al, 2009
- Sher L., 2001
- Jaiswal Rahul et al, 2011
- Nathani Neeru et al, 2013
- Abhyanga - rubbing with unctuous substance, inunctions
- Ashana - eating, food
- Ashita - eaten, the place where anybody has eaten
- Atra - in this respect, in this place , in this manner, at this time
- Audaka - living or growing in water, relating to water, aquatic
- Audbhid - breaking through the Earth
- Avagahana – immersion, bathing
- Avashyaya - dew, hoar-frost
- Adana - taking, receiving, taking away or off, obtaining, a cause of disease
- Adhya - to be eaten, edible, food, grain
- Agneya - belonging or relating to fire or Agni
- Anupa - belonging to a watery place, marshy places or animals
- Bhavat - being, present
- Bhrita - borne, carried, gained, acquired, filled, full of
- Charya - to be practiced
- Cheshta - gesture, manner of life, behavior, action, endeavor, manner of performing
- Harmya - a large house
- Jangala - rid, wild, sparingly grown with trees and plants
- Jentaka - dry hot bath
- Kleda - dampness, wetness, moisture
- Pragvata - easterly wind
- Prashasta - considered fit or good, more excellent, auspicious, happy, praised
- Ritu - Season, an epoch, any settled point of time, period or division of the year, time appointed for any action
- Saumya - cool and moist, relating or belonging to soma (moon), placid, gentle, mild
- Satmya - wholesome , agreeable to nature or natural constitution, habitual
- Sevya - to be inhabited, to be followed, to be approached, to be practiced
- Udgharshana - rubbing the skin with hard substances
- Udamantha - a particular mixture in water
- Udvartana - rubbing, or reducing the body with fragrant unguents
- Utsadana - rubbing, anointing
- Varna - lustre, outward appearance or complexion, character , nature quality, color
- Visarga - giving, granting, bestowal, sending forth, voiding, liberation, emission, discharge
- Yusha - soup, broth, the water in which pulse of various kinds has been boiled
- Tasya – his, for him, of him, for that purpose
- Varjya – to be excluded, avoided, given up, shunned